This directory holds all transformations/optimizations newly implemented for SCC (T4).
The table below summarizes how the main files in this directory map to concepts described in the T4 paper. The order of rows in this table matches the order in which transformations are applied to application code when the compiler runs.
| File | T4 concept |
|---|---|
| InsertHeartbeats.cpp | Heartbeats |
| CreateParallelizableCopy.cpp | CPS conversion |
| Bundling.cpp | Privatization, bundling |
| Fractalizer.cpp & LoopIterDetacher.cpp | Task delineation, order, spawn |
| LoopCoarsen.cpp | Loop coarsening |
| LoopExpansion.cpp | Loop expansion (spawner trees) |
| SpatialHints.cpp | Spatial-hint generation |
| LowerToSwarm.cpp & SwarmABI.cpp | Task lifting |
See the individual files to learn about the implementation of each transformation pass.
The order in which these passes run, interleaved with other pre-existing LLVM
simplification passes, is determined by
PassManagerBuilder::populateModulePassManager()
in lib/Transforms/IPO/PassManagerBuilder.cpp